alert http $HOME_NET any -> $EXTERNAL_NET any (
msg:"ET MALWARE Kimsuky Related CnC Activity";
flow:established,to_server;
http.method;
content:"GET";
http.uri;
pcre:"/https:\/\/[a-z0-9]{8}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{4}-[a-z0-9]{12}.[a-z]{3,12}.com\/[a-z]{3,4}\/[a-z0-9]{6}_[a-z0-9]{32}/";
content:".xls?dn="; fast_pattern;
content:".xls"; endswith;
reference:url,github.com/eset/malware-ioc/tree/master/kimsuky/hotdoge_donutcat_case;
classtype:trojan-activity;
sid:2034696; rev:1;
metadata:affected_product Windows_XP_Vista_7_8_10_Server_32_64_Bit, attack_target Client_Endpoint, created_at 2021_12_13, deployment Perimeter, performance_impact Low, confidence High, signature_severity Major, tag Description_Generated_By_Proofpoint_Nexus, updated_at 2021_12_13;
)